Roll out the pastry on a floured surface to create a long rectangle about 24cm x 48cm. Using a sharp knife, cut the pastry into 3, lengthways, to make 3 long strips. Then cut each strip into 6 to make 6 x 8cm squares, making a total of 18 squares. Transfer to 2 baking trays lined with baking paper. Prick each square all over with a fork, then chill for 20-30 minutes until firm. Preheat the oven to 220°C, fan 200°C, gas 7.
Place 1 sheet of baking paper and another baking tray or roasting tin on top of each set of pastry squares to keep them from puffing up. For this recipe, you want thin, really crisp pastry layers. Bake for 20 minutes until crisp, swapping the trays over in the oven after 10 minutes to ensure even colour. Remove from the oven, taking off the top trays and paper, and preheat the grill.
Dust the pastry squares thickly with icing sugar and grill for 1-2 minutes until caramelised. Watch them closely, as they burn easily. Leave to cool completely.
Mix half a teaspoon of rosewater and 1 tablespoon of honey together in a bowl. Slice the strawberries and add to the bowl; toss gently. Set aside at room temperature.
Beat the cream cheese and yogurt with the remaining honey and rosewater. Stir in half the pistachios; transfer to a piping bag with a 1cm plain nozzle (or see below).
Lay out 12 of the pastry squares and pipe 9 blobs of the cream cheese mixture on to each one, or spoon the mixture on to the pastry using a teaspoon. Scatter with a few chopped pistachios. Divide the sliced strawberries between them. For each millefeuille, stack 2 prepared layers on top of each other then top with a final pastry square, caramelised side up. Scatter with the remaining pistachios.